The use of in-line ball valve assemblies in subsea tree intervention tools is fairly well known in the art. The ball valves are used to open and close a central flow passage in the assembly and are typically hydraulically actuated. In some cases, the ball valves are designed to shear coiled tubing or wireline in the event of an emergency.
In one type of prior art device, U.S. Pat. No. 5,551,665, a pair of control pins slide radially inward within slots to actuate the ball between the open and closed positions. Similarly, PCT Publication No. WO 96/35857 shows control pins which slide axially to accomplish the same objective. Regarding the shearing function, U.S. Pat. No. 4,160,478 shows a quadrant of a ball valve tool having a cutting mechanism which will cut coiled tubing in only one place. This is advantageous since a small loose segment of tubing would otherwise be cut. The segment could then fall into the bottom of the well and create problems. Another prior art device, U.S. Pat. No. 5,284,209, has a ball valve that shears coiled tubing in only one place due to a recess in the housing.